TcpdumpApplication

CVE-2016-7985

CRITICAL · 9.8 CVSS v3.0 Published 2017-01-28
Fix available
A fix is available. Upgrade to after 4.8.1 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The CALM FAST parser in tcpdump before 4.9.0 has a buffer overflow in print-calm-fast.c:calm_fast_print().

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A buffer overflow vulnerability exists in the CALM FAST protocol parser (print-calm-fast.c:calm_fast_print()) in tcpdump versions prior to 4.9.0. The overflow occurs during packet parsing, potentially allowing remote attackers to execute arbitrary code via specially crafted CALM FAST packets.

MitigationUpgrade tcpdump to version 4.9.0 or later to patch the buffer overflow vulnerability in the CALM FAST parser.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
TcpdumpApplication
Affected:<= 4.8.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check if tcpdump is installed
    Run 'tcpdump --version' or 'which tcpdump' to locate the tcpdump binary
    Affected if tcpdump is not found on the system - not applicable for detection
  2. Determine installed tcpdump version
    Run 'tcpdump --version' and examine the version number in the output
    Affected if The version number is 4.8.1 or lower, or if the version cannot be determined but tcpdump is present
  3. Check for CALM FAST traffic capture capability
    Verify tcpdump has pcap library support by running 'tcpdump -h' or checking if it can capture on network interfaces
    Affected if tcpdump is installed and can capture network traffic - the CALM FAST parser processes packets during analysis of captured traffic
  4. Cross-reference version with affected range
    Compare your installed version (from --version output) to the affected range of <= 4.8.1
    Affected if Your version is 4.8.1 or any version prior to 4.9.0, making the CALM FAST parser vulnerable to buffer overflow when processing specially crafted packets

You are affected if tcpdump version 4.8.1 or lower is installed and actively used to analyze network traffic that may contain CALM FAST protocol packets.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 4.8.1
Interim mitigation

Upgrade tcpdump to version 4.9.0 or later to patch the buffer overflow vulnerability in the CALM FAST parser.

Recommended fix High confidence

tcpdump 4.9.0 or later

  1. 1. Check the current installed version of tcpdump by running 'tcpdump --version' or 'rpm -q tcpdump' / 'dpkg -l tcpdump'
  2. 2. Upgrade tcpdump to version 4.9.0 or later using your system's package manager: 'apt-get update && apt-get install tcpdump' (Debian/Ubuntu), 'yum update tcpdump' or 'dnf update tcpdump' (RHEL/CentOS/Fedora), or 'emerge --ask net-analyzer/tcpdump' (Gentoo)
  3. 3. Verify the upgrade was successful by running 'tcpdump --version' and confirming the version is 4.9.0 or higher
  4. 4. Test that tcpdump functions normally with your typical capture commands
Caveat Standard upgrade; no major breaking changes expected for this minor version bump. As a security-critical update, any functionality changes are outweighed by the vulnerability risk.

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Tcpdump Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,408.

Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2016-7985 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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